Chapter Two Flashcards
What does p̂ (p-hat) stand for?
The sample proportion
What does p stand for?
The population proportion
What is a way to describe two categorical variables in a table?
Two-Way table
When is a data set skewed to the right?
When the data is piled up to the left and the tail extends far out the right.
When is a data set skewed to the left?
When the data is piled up to the right and the tail extends relatively far out to the left.
What is the difference between a symmetric and a bell-shaped distribution?
The bell shaped distribution is both symmetric and bell-shaped, while the symmetric distribution is just symmetric.
What does μ (mew) stand for?
The population mean.
What does x̄ (x-bar) stand for?
The sample mean.
What does n stand for?
The sample size.
What does N stand for?
The population size.
In a study regarding the catches of all NFL receivers (WR or TE), would n or N be the total number of receivers?
N
What does m stand for?
The median.
What does resistance mean?
A statistic’s ability to remain unaffected by extreme values.
If a graph is skewed to the right, which is larger, the median or the mean?
The mean would be greater.
If a graph is skewed to the left, which is larger, the median or the mean?
The median would be greater.
What is the symbol for standard deviation of a sample and what does it represent?
s represents the standard deviation (measures how spread out the data are rom the mean.
What is the symbol for standard deviation of a sample and what does it represent?
σ represents the standard deviation (measures how spread out the data are rom the mean.
What is the formula for the standard deviation of a sample?
S= √ (the sum of (x - x̄) squared / (n - 1)
What are the rules for the 95% rule?
95% of the data in a sample from a bell shaped distribution should fall between the values of (x̄ - 2s) and (x̄ + 2s)
What is the formula for Z-score?
Z score = (The data value in question - x̄) / s
Which should be used as the measure of center for skewed data?
The median.
Which should be used as the measure of center for symmetric data?
The mean.
What is the formula for the LF and UF?
LF = Q1 - 1.5 (IQR)
UF = Q3 + 1.5 (IQR)
Where are the explanatory and response variables located on a scatterplot?
The explanatory on the x - axis
The response on the y - axis
What is the symbol r used for?
The sample correlation.
What is the symbol ρ (row) used for?
The population correlation.
What is the coefficient of determination?
The symbol r squared is the coefficient of determination and it is the percentage of the variation in the y-values that is explained by the linear relationship between x and y.
How is sample correlation calculated?
r = (the sum of all (x times y) - (n times x̅ times ȳ)) / ((n -1) times standard deviation of x times standard deviation of y)
What is the formula for the residual (error of estimation)?
The actual y value - the y value found using the line of least regression
Understand Simpson’s paradox.
See 2.7 notes
Understand graphical misrepresentaions.
See 2.7 notes (last page)
